This invention relates to a shifting-field type permanent-magnet motor.
Conventionally, a DC motor is adapted to generate a magnetic field by a stator consisting of a yoke formed to have magnetic poles, and supply an armature, which is disposed in the magnetic field to serve as a rotor, with a direct current via brushes, whereby the armature is rotated.
In addition, a DC motor which uses a rotor having a permanent magnet also is well known.
However, the conventional DC motors of the type described above are difficult to start smoothly and consume a large amount of electric power. Furthermore, problems are encountered in terms of driving these motors at a high torque and in a reliable manner.